Hi.

I want to develop custom 404 error page with same UI as my sharePoint Site and to show a message for "File not Found"

but where to

Hi,

The 404 error page exists in %systemdrive% \Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\TEMPLATE\LAYOUTS\1033(English language ID)\sps404.html

Below is the method replacing the built in 404 page:

1. Copy the Sps404.html file to a temporary folder.
2. Rename the Sps404.html file. Such as My404.html
3. Customize the My404.html file using an HTML editor.
4. Save it back to above address
5. Run the following PowerShell cmdlet to update the change:
$webapp =Get-SPWebApplication <a href="http://:<port">http://<serverUrl>:<port>
$webapp.FileNotFoundPage = "Custom404.html"
$webapp.update()

Thanks,

Kenon Yin